Constitution Square

Your Guide

Constitution Square is a prime example of transit-oriented design in downtown Washington. The project includes office, residential, hotel, and retail uses, embraced by a streetscape that expresses the idea of sustainability with style.

The streetscapes along 1st Street NE and M Street exhibit the value of urban design guidelines, but also demonstrate how guidelines can be interpreted in an artful way. The sidewalks on the M Street side generally follow the guidelines, with concrete walks and generous tree pits at curbside. The sidewalk is interrupted at key building entries with rich, bluestone welcome mats of paving.

The sidewalk on 1st Street, which was designed by Parker Rodriguez, bends the guidelines with the insertion of a series of gently curving bioretention filters. The interplay of their form creates a sinuous walk, breaking up the relentless orthogonal geometries of adjacent blocks. That these bioretention planters also provide improvements to neighborhood water quality makes them even more of a benefit to the city, as the plants soak up the rain and cleanse it before releasing it into the watershed. The banded pattern of the plants – grasses, shrubs , and trees – create a regular rhythm to the walking experience in counterpoint to the lyrical lines of the bioretention planters themselves.

A Sinuous Line

The sidewalk on 1st Street features a tree pit zone at curbside, a retail zone at the building edge, and a central bioretention planter zone. These planters feature gently curving forms, resulting in a walk that meanders along a sinuous line.

Image: Dennis Carmichael

Bioretention

Detail of the curb cuts in the bioretention planter that allows the stormwater to flow from the sidewalk into the planter, set about one foot lower than the sidewalk.

Image: Dennis Carmichael

Conveying Water

A series of benches follow the sidewalk, backing up to the bioretention planters. Note the trench drain that conveys the water from the street into the planters.

Image: Dennis Carmichael

Cobbles and Horsetail Plants

The bottom of the bioretention planter features alternating bands of river-washed cobbles and horsetail plants. The cobbles serve to reduce the velocity of the stormwater runoff, while the plants absorb the toxins that come with the first flush of that runoff.

Image: Dennis Carmichael

An Alternative to Cars

A Capital Bikeshare station is located on the M Street side, to offer an alternative to motorized transport.

Image: Dennis Carmichael

A Diversity of Plant Life

A variety of perennials and annuals fill the tree pits at curb side.

Image: Dennis Carmichael

An Elegant Edge to the Walk

The standard streetscape guidelines create a consistent landscape edge at curbside and a generous swath of sidewalk for circulation. What was added here is the linear planter to screen a series of underground transformer vaults, providing an elegant edge to the walk.

Image: Dennis Carmichael

A Carpet of Bluestone Pavement

The entry to the residential tower on M Street is marked by a carpet of bluestone pavement that spills across the sidewalk, a series of stone seats, and cast-concrete planters with annuals.

Image: Dennis Carmichael

The Lyrical Quality of the Landscape

Detail view of the interplay of the curving bioretention planters as they course up and down 1st Street, providing a lyrical quality to the landscape.